The invention relates to a sliding device for a fifth wheel with an upper part bearing the fifth wheel and with a base frame arranged under the upper part.
Sliding units are devices that bear the fifth wheel and make it possible to slide the fifth wheel longitudinally to the vehicle and lock it in various positions. Such sliding units are known from DE-AS 17 80 488 or EP 0 503 954 A1.
Semi-trailer trucks, as a rule, have framework constructions consisting of two C-profiles open toward the inside, which are linked with cross members. Fastened to this main frame, as a rule, are two auxiliary frames, to which, in turn, assembly components such as sliding units can be fastened. The sliding units mostly feature flat-shaped base frames, which are either screwed or welded to the auxiliary frame.
Thus, the overall system consists of three units: the fifth wheel, the sliding unit and the auxiliary frame. First, the auxiliary frame is screwed onto the main frame by the manufacturer of the semi-trailer truck, then the sliding unit is fastened, with the fifth wheel mounted on it, to the auxiliary frame.
The overall frame assembly of the vehicle is subject to certain variations in its overall dimensions, in particular its width, which are caused by unavoidable measurement tolerances, as well as intended variations in material strengths in the components used.
The problem of this invention consists of simplifying assembly by means of an improved sliding device which takes these measurement tolerances and, at the same time, the overall weight of the vehicle frame system/sliding system into account.
This problem is solved by a sliding device, whose base frame comprises two longitudinally extending angular profiles, which are linked with each other by means of two detachable and slideably mounted tie-bars and with which each angular profile has initial retaining means, which interact with second retaining means of the upper part in such a manner that the upper part can be longitudinally and transversally displaced relative to the base frame.
The longitudinal and transverse directions are relative to the longitudinal and/or transverse axle of the vehicle.
Since the base frame has angular profiles, it can be directly fastened to the main frame of the semi-trailer truck without any additional auxiliary frame. Tolerances concerning the distance from both frames of the semi-trailer truck can be compensated by arranging the tie-bars to be slideable. By preference this is achieved by providing the tie-bars with longitudinal holes, so as to allow adjustments to be made to various frame widths.
Since the weight of the auxiliary frame is completely eliminated, the overall weight of the vehicle frame-plus sliding device-system is significantly reduced. The vehicle auxiliary frame can be dispensed with, since the base frame that is the object of this invention assumes its function, thus also simplifying assembly. In so doing, neither the technological requirements (equipment) on the final flow line nor the semi-trailer truck manufacturer""s structural designs of the main frame are altered.
The upper parts of the sliding device are rigid, as a rule, so that no adjustments to varying frame widths of the semi-trailer truck are possible. If the vehicle width changes, then the width of the base frame is adjusted by shifting the tie-bar. A rigid upper part requires relative slideability between the upper part and the base frame. To make this possible, each angular profile comprises initial retaining means, which interact with the second retaining means of the upper part in such a manner as to allow the upper part to slide, not only in the vehicle longitudinal direction, but also in a transverse direction, to adjust to the various widths ultimately predetermined by the frame construction of the semi-trailer truck.
This is achieved by means of a preferred embodiment involving the arrangement of a runner on the angular profile, which comprises an upwardly projecting leg body with one leg pointing inward and one pointing outward. In the simplest case a T-runner can be used, however, as per another embodiment, there is also the possibility of arranging both legs in a vertical direction.
The second retaining means, which are arranged on the underside of the upper part, consist of C-frames enclosing this leg. Here the C-frames and legs are coordinated in such a way as to provide gaps in a horizontal direction between the legs and the C-frames, to permit transverse sliding. So doing, the C-frames enclose the legs to the extent where the upper part may be slid inward or outward without the C-frames coming into contact with the legs.
As per another embodiment, the inside or outside leg may form a catch ledge. The upper part is equipped with one or more blocking pieces that catch on the catch ledge of the upper part at the appropriate position and thus fix the upper part.
By preference, the angular profile, the runner body and one of the two legs make up a one-piece assembly. This will further simplify manufacturing.